My sons are all sensitive to glutens (not celiac), but I do let them cheat occasionally. But at Halloween, so much of the candy has glutens, that they can't eat a lot of it. I actually end up buying them some gluten free candy to make up for what I take away. How do you handle the food sensitivities during Halloween?
Ds1 (age 10) has celiac disease. He has two younger brothers so they trade. Ds1 takes out all the gluten-containing candies and trades them with his brothers.
Your idea of buying extra candy to make up for the difference is similar.
I gave my son other things, instead. We took the candy from the neighbors we knew to our local bookstore, where we knew some or the workers. He got to show his costume to more people, and the candy was put in the breakroom for all the workers. He enjoyed the extra attention.
Or you can give books in trade of candy, or a game, or homemade treats.
Consult this list of gluten-free halloween candies 2012
I keep in mind a few safe items, like smarties and original butterfingers, for him to eat while out. Then sort out the rest when we get home. Give that to daddy.